The Mount Desert Island Biological Laboratory seeks NIDDK R13 support for the fourth annual national course for renal fellows and medical residents, Origins of Renal Physiology, September 3-10, 2011, at the Mount Desert Island Biological Laboratory (MDIBL), in Bar Harbor, Maine. The proposed course provides renal fellows, residents who will enter nephrology, and junior faculty, with hands-on research training in fundamental concepts of homeostasis and exposes them to the classical experiments that form the foundation of renal physiology and nephrology. Six course modules are proposed: glomerular filtration, proximal tubule function, thick ascending limb cotransporters, salt secretion and balance, collecting duct sodium transport / ENaC, and water homeostasis. An enrichment module in genetics will be added in 2011. Each of the six modules runs in three consecutive two-day rotations (Monday-Tuesday, Wednesday-Thursday, and Friday-Saturday), with the first day of each rotation involving intensive experimental work, and the second day involving analysis and presentation of the work to the entire conference group. Each trainee will complete three of the six planned modules during the three rotations. Origins of Renal Physiology is entirely unique among national renal short courses. The course provides participants with research tools that give them a deeper understanding of concepts of physiological homeostasis which is difficult to attain during normal clinical training schedules. The course is open to both renal fellows and, since 2010, medical residents entering nephrology. Fellows and residents alike benefit from close interactions with senior investigators in renal physiology who lead the course modules. Residents, in particular, benefit by working with fellows from different programs and sharing their insights into renal research and nephrology. The course is described on the MDIBL website (http://www.mdibl.org), and in a recent editorial in J. Am. Soc. of Nephrology (Zeidel et al., JASN 19: 649-50, 2008). Requested funds will cover trainee subsistence, research supplies, and travel;therefore, tuition costs carried by the trainee will be significantly reduced. PUBLIC HEALTH RELEVANCE: The course "Origins of Renal Physiology" is highly relevant to biomedical research and the advancement of human health. Course participants are 30 renal fellows and medical residents who will specialize in nephrology. This number represents about 10% of the annual "class" of renal fellows in the United States, permitting the course to have a significant impact on the training of fellows nationally. Course faculty include clinical nephrologists and investigators. The trainees perform experiments to elucidate kidney function including glomerular filtration, proximal tubule, thick ascending limb, and collecting duct transport, water homeostasis, cellular trafficking of transporter proteins, and the structure-function of transporter proteins such as aquaporins, urea carriers, ENaC and the Na/K/2Cl cotransporter. A new genetics module will demonstrate genetic mutations indicated in human kidney diseases.